"GIYF" is often given as curt response to a question that perhaps should not have been asked, or was poorly researched.

This phrase carries several insinuations, firsty that the poster did not bother to try to
find his/her own solution to a problem, but instead 'dumped it' to the forum/chat group to solve.

It is a shortened, dismissive, response to a question deemed inappropriate. Similar to RTFM, it conveys the intonation that "If you didn't bother to
spend 15 seconds searching for the answer on your own, I'm not going to waste a complete sentence responding to you"

As with RTFM, it carries a cruder double-entendre along the lines of "Get It Yourself F**ker"

An acronym telling somebody to Google something.
It is originally short for "Google Is Your Friend", but also has evolved to mean "Google It Yourself, Fucker" or "Google It, You Faggot".
Which version you take it as is entirely up to you.